The present invention relates to a light radiator for effectively diffusing and radiating light rays which have been transmitted through an optical cable or the like to the outside of the optical conductor cable.
The present applicant has previously proposed various ways to focus solar rays or artificial light rays by the use of lenses or the like and to guide the same into an optical conductor cable thereby transmitting them onto an optional desired place through the optical conductor cable. Solar rays or artificial light rays transmitted and emitted in such a way are employed for inducing photo-synthesis and for use in illuminating or for other like purposes, as for example, to better promote the cultivation of plants.
However, in the case of utilizing the light energy for cultivating plants as mentioned above, the light rays transmitted through the optical conductor cable have directional characteristics. Supposing that the end portion of the optical conductor cable is cut off and that the light rays are emitted therefrom, the radiation angle for the focused light rays is, in general, equal to approximately 46.degree.. That is quite a narrow field. In the case of utilizing the light energy as described above, it is impossible to perform a desirable amount of illumination by simply cutting off the end portion of the optical conductor cable and by letting light rays emit therefrom. Therefore, the present applicant has already proposed various kinds of light radiators capable of effectively diffusing light rays which have been transmitted through an optical conductor cable and for radiating the same, as illumination, over a desired area.